The increasing dominance of data traffic in the Internet is pushing network service providers to deploy complex network architectures with sophisticated new optical components for exploiting the tremendous capacity of optical fiber. The fundamental enabling technology is wavelength division multiplexing (WDM), whereby multiple data streams are simultaneously transmitted on distinct wavelength channels. Tunable components such as optical switches, tunable transceivers, and tunable filters have been made cost effective in recent years. These components introduce configurability into networks, enabling network architects to envision and study practical means of deploying automatically-controlled dynamic optical networks.
The Time-domain Wavelength Interleaved Networking (TWIN) architecture has been introduced as an efficient and cost-effective alternative to both Optical Circuit Switching and Optical Burst Switching, see, e.g., I. Saniee et al., “A New Optical Network Architecture that Exploits Joint Time and Wavelength Interleaving,” IEEE/OFC Technical Digest, February 2004, the disclosure of which is incorporated by reference herein. TWIN utilizes fast tunable lasers and burst-mode receivers at the network edge, and wavelength selective cross-connect (WSXC) for passive routing of optical signals (bursts) in the network core.
Typically, in the TWIN architecture, propagation delays (e.g., about 1 millisecond per 200 kilometers) significantly dominate the scheduling time-scale (on the order of tens of microseconds) and thus are non-negligible. Thus, for a nearly static load, pre-computed centralized scheduling is feasible, e.g., as described in K. Ross et al., “Scheduling Bursts in Time-domain Wavelength Interleaved Networks,” IEEE J. Select. Areas Comm., vol. 21, pp. 1441-1451, November 2003, the disclosure of which is incorporated by reference herein.